Add GitHub Actions workflow for CI/CD

.github/workflows/deploy.yml

@@ -0,0 +1,20 @@
+name: Deploy to VM
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v2    
+    - name: Build and push backend image
+      run: |
+        docker build -t my-backend:latest -f Dockerfile .
+        docker push my-backend:latest